#include<iostream>

using namespace std;

const int N = 100010;
int n,m;
int a[N],s[N];

int main(){
    scanf("%d%d",&n, &m);
    for(int i = 1; i <=n; i++) scanf("%d", &a[i]);
    for(int i = 1; i <= n; i++) s[i] = s[i-1] + a[i];

    while(m--)
    {
        int l,r;
        scanf("%d%d", &l, &r);
        printf("%d\n", s[r] - s[l - 1]);
        
    }

    return 0;
}